public class GettingBeginningLoop {
  public node gettingBeginningLoop(Node n) {
    Node head = n;
  //Pre-requisite: need to know it's infinite loop already.
    Node slowRunner = head;
    Node fastRunner = head;
    
    slowRunner = slowRunner.next;
    fastRunner = fastRunner.next.next;
    
    while(slowRunner.next != fastRunner.next) {
      slowRunner = slowRunner.next;
      fastRunner = fastRunner.next.next;
      }
      
    return slowRunner;
    }
}